fix(package): books.start runs the real integrity check (U0b)

books.start passed Integrity::default() to the attention engine, so it
asserted "database matches, no file failures". On a book whose database
differs from the journal, or whose stored file is missing or corrupt, the
viewer showed the database/stored-files items and the server did not: the
two lists diverged exactly where they matter most.

Call find, which computes the check: every distinct stored blob is read
and hash-checked once (a damaged blob is still reported per attachment
filed from it), and Store::disk_check now makes the viewer's comparison
through a snapshot of its data directory instead of reporting a match.

The parity test now damages its own fixture (removes the receipt's blob,
then changes a projected account row) and asserts both lists still agree
item for item and both name the damage. On the demo books (138
attachments, 138 distinct blobs, debug build) books.start takes about
0.26 s warm, 0.29 s cold, so the real check costs no decision.

crates/ledger-mcp/src/tools/kept.rs

@@ -834,12 +834,7 @@ impl BooksServer {
                 financing_accounts: &cfg.roles.financing,
                 investing_accounts: &cfg.roles.investing,
             };
-            let attention = ledger_package::find_with(
-                store,
-                today,
-                &attention_settings,
-                &ledger_package::Integrity::default(),
-            );
+            let attention = ledger_package::find(store, today, &attention_settings);
             for a in attention.iter().filter(|a| a.tool.is_some()).take(12) {
                 let Some((tool, args)) = &a.tool else {
                     continue;